George g



G. G. TAYLOR AND I. E. KNAPP. In.

PROCESS OF PRODUCING AMMDNIA AND AMMONIUM COMPOUNDS.

APPLICATION FILED SEPT. l3. l9! 1.

1,315,534. PatentedSept. 9, 1919.

FIG. 1

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3 r FOA/YAC #ar 200a. ='.'x

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3 INVENTOR M 7 sure, or to mix the material with some sub- UNITED STATES PATENT OFFICE.

enema a. trance, orcnAr'roN, AND xsmoun a. KNAPP, JR, or conAoroms,

PENNSYLVANIA.

rnocnss or raonucme AMMONIA AND AMMONIUM conro Nns.

Specification of Letters Patent.

, Patented se ta, 1919.

A lication and September 13, 1917. Serial No. 191,135.

To all whom it may concern:

Be it known that we, G'Eouon G. TAYnoa 4 monium Compounds; and we do hereby declare the followin to be a full, clear, and exact description t ereof.

Our invention relates to the manufacture r of ammonia or ammonium compounds from the so-called fixation products of the interaction of carbids with nitrogen gas. v In such production of ammonia or ammonium compounds, great difiiculty has been experienced in converting a large percentage of the nitrogen to ammonia by the use 0 steam.

In order to facilitate this conversion, it has been custom'a containing materia 'with steam under presstance,such as sodiuin carbonate, lime or sodium sulphate,-and then subject this mass to the action of water and steam in an autoclave, or a device for carrying 1 out chemical reactions with the aid of heat and pressure.

In the rocess herein described, the nitrogen-containing material is not mixed with any other substance, nor is it necessary that the reaction be carried on under-pressure equal to or greater than atmospheric pressure, and we are able to obtain approxr mately 92 to 95 per cent. of the nitrogen in the form of ammonia gas and ammonium compounds. It is one of the advantages of this invention, therefore, that we may carry on our reactions in the production of ammonia at, above or below atmospheric pressure. We have found inpractice, however, that for practical cons derations. it up ears best to carry on the reactions at atmosp eric.

pressure; y

In our rocess for the production ofammonia and ammonium compounds, the nitrogen-containing materials uch as that obtained from t e action of nitrogen gas upon calcium cal-bid, for examp'lemay be carried'out in different ways, without affecting the principle underlying our invention, provided that the material be subjected, at a temperature below 350 0., to the action to heat the nitrogenof steam or water until a point of approximate or complete saturation is reached. This ma Jecting tli above 100 C. by the application of steam or' water. The temperature is then raised to or above a temperature ofapproximately' 450 cent.

Vhile in our process a variety of nitrogen compounds may be employed, we have found that the process is particularly adapted for treating such nitro en compounds as are produced by the com inations of metal, carbon and nitrogen, such asare described in our com anion application, Serial No. 190,875, fi ed on the 12th day of September, 1917. One of the principal substances, therefore, with which the present process is concerned is what we term dimetal isocyanid,

though it is to be understood that, our invention is in no way limited to thetreatmenl' of thissubstance, but we may employ not only any of the com ounds produced by the process-hereinafter riefly referred to, but also any other nitrogen, compounds, which are susceptible to reduction by steam.

The products which we prefer to employ andparticularly dimetal 1socyanidmay be produced inthe following manner A metal oxid--such as calcium oxid, for exanipleis mixed with a suitable proportion of coal and is coked referably m a by product oven whereb t e ammonia, light oils; and other valuable products are recovered, and the gas from which may be used to furnish all or a art of the heat necessary to complete the col iing process.

' The resulting mixture, 00 of a rigidly cemented mass'ofmetal oxid and coke, is then withdrawn from the furnace, and, if necessary or desirable, crushed by any suitable form of crusher. It is then transferred in whole orin part,.or from time to time in such increments as are most suite able, to an electric furnace,

The electric furnace employed in carr dug out this process may be of any approved design, but we prefer to employ a furnace which consistsof one or more pairs of electrodes supported insuch a way as to be easily adjusted, but preferably to form an take place below 100 C. by sub e material either to wet steam or water or it may take place at a temperature angle of over 90 with each other, and the hearth and collects at ametal oxid and coke will readily fall be tween them. A hearth of carbon or other suitable material may be placed below the pair of electrodes to form a barrier whereby the coke mixture is held between the ends of the electrodes, and thereb is exposed to the fullest possible action 0 the electric current.

The coke mixture prepared as above is then acted upon by the electric current, which is preferably an alternating current with volta e below 100, although we do not limit .oursdlves to this, and a metal carbid is formed. The carbid so formed immediately flows down between the electrodes and the oint sufliciently far from the heat zone so t at its temperature is relatively low. The carbid so collected may be removed from time to time as necessary or desirable, or it may fall upon a conveyor and be continuously removed.

. The carbid once formed does not dissociate into metal and carbon since it is immediately cooled below its dissociation point, and it is sufliciently cooled so that it is not acted upon by the oxygen .in the air to form oxid of carbon and metal oxid.

The metal carbid so produced is very pure and free from metal oxld', carbon, and metal,

and, therefore, is a far superior product for the purposes hereinafter to be described, in-

.asmuch as the yield of the products is increased and their production facilitatedby the use of a carbid of a high degree of purity.

The metal carbid so formed, or a metal car'bid made b other processes, is then crushed to a sultable size by a ball mill or other device, and is put into a furnace or retort of such design that the products of combustion, if combustible materials are used for heating, are not allowed to penetrate to the interior of the furnace or retort in such amount as to produce an injurious effect upon the roduct and thereby cause decompositionof the metal carbid, or of the products subsequently formed.

Before introducing the carbid into the furnace, it may be mixed with a suitable proportion of a catalyst, such as a metal chlorid, fluorid, or a mixture of chlorid and fluoridsuch as a mixture of sodium chloridand calcium fiuorid, for examplewhereby the combination between the nitrogen and the metal carbid is facilitated and proceeds rapidly at a much lower temperature than would be necessary if the above-mentioned catalyst were absent.

A current'of nitrogen s, which ma have benprepared by purifying the pro acts of combustion of the coking retorts above referred to, by the fractional distillation from liquid air, or by other means of preparing nitrogen gas, is caused to pass over and through the mass of carbid.

'perature of the furnace Whether or not a catalyst is used, a combmation between the nitrogen and'the carbid 1s eflected very rapidly whenever the temperature is raised to or above a dark red eat, and heat is liberated by the reaction,

whlch serves in part to maintain the reacting mass at the proper temperature. The above brief outline of the method of preparing the materials, which may be employed 1n the process forming the subject of this invention, is more fully described in the specification of our companion application above referred to.

The nitrified product so formed contains some lime, a trace of carbid, and one or more compounds containing metal and nitrogen, or metal, carbon, and nitrogen, together with a certain amount of carbon liberated by the reaction, and a small amount of inert matter, mostly from the ash in the coal, and impurities from the metal oxid used. The amount and nature of these com ound's may be controlled to a certain extent y the; temand by the rapidity of the reaction, which may be accelerated or otherwise influenced by the addition of ,a catalyst.

Among the combinations which are thus formed by the action of nitrogen on a carbid, are isocyanid-or, as we term it, dilnetal 9;, isocyanid. There may also be formed nitrid, cyanamid, cyanid and various other compounds containing metal, carbon and nitrogen.

The predominant combination, however, when the temperature is below 1000 cent., is usually the dimetral isocyanid of the formula M N C in which M is a metal, and when conditions are properly regulated, this combination is formed to the practical eX- clusion of all others. 1. i

The nitrid formed is from such small amount of pure metal as may be present in the reacting mass; the other compounds,- such as' dimetal isocyanid, isocyanld, cyanamid, etc-are formed by the action of the nitrogen on the carbid,

The mixture from the nitrifyin furnace, consisting in whole or in part 0 the new and valuable compounds, particularly di- 'metal isocyanid, may be used with special apparatus for carrying out what we term an intermittent process; and Fig. 2 illustrates an apparatus for carrying out what we term a continuous process.

In Fig. 1, 1 indicates a suitable retort in which the nitrified material 2 is to he treat mum ed. Said retort has a steam connection 3 and an outlet for leading to any suitable form of condenser 5 through which the material isconveyed and from which it is conducted by a pipe 6 to a suitable scrubber 7, fromwhich the CO may escape by pipe 8.

In carrying out our improved process, the material is treated with water in the form of liquid or vapor either before or after the material is placed within the retort 1; and heat is gradually ap )lied to the retort in any desired manner. he roduction of ammonia begins almost imme lately,

and continues steadily to increase as the temperature of the retort gradually rises, until the material in the retort has reached approximately 500 cent., when a copious evolution of carbon dioxid gas occurs, and the resulting product consists very largely of ammonium carbonate and bicarbonate formed by the reaction between ammonia, water and CO and such other ammonium compounds as may be formed at the temby the mixed gases and vapors during their passage through the retort and through the condenser.

site the hopper9 may be vapors or gases from the veyed by; a pipe 13 to a condenser and scrub- -1nay be utilized as When the reaction is over and the condensate from the retort contains very little or no ammonia, the retort is cooled, cleaned and a new charge is placed therein.

Referring now to Fig. 2 of the drawing, which illustrates an apparatus for carrying out our process continuously, 9 indicates a suitable hopper from which the nitrified material may be supplied to a suitable form of conveyer having a steam connection, as at 11. At the end of the conveyor oppoconnected a suitable the residual material taken place and the reactions are conout,

container 12 to receive after the reaction has her, as efore described.

In this form of apparatus. the conveyer the retort through which the charge is gradually and continuously fed, and in which it encounters a steady increase in temperature up to the point where the last of the ammonia and ammonium compounds is given oflz',-whenee the residual material falls into the container 12 and may be removed by such device as does not interfere with the continuous operation of the retort. During this heating operation, steam is led through the retort to the conveyor, and together with the ammonia or other products, passes through a condenser and scrubber, as heretofore described.

Thecondensate consisting of water in which is dissolved ammonia, ammonium carbonate, bicarbonate and other ammonium ompounds may be collected as such and the ammonia distilled ofi' and recovered by suit able means, while, the water solution of ammonium carbonate, bicarbonate and other material, and

compounds is concentrated and the salts crystallized therefrom; or the solution of ammon um carbonate, bicarbonate, or other ammonium compounds may be treated with a base as sodium hydrate, for example and thereby decomposed intoammonia gas, which may be distilled oil and recovered.

The condensate may also be led into sulfuric acid and the resulting ammonium sulfate recovered by crystallization, or other well-known means; or, the condensate may be led into nitric acid, and the ammonium nitrate recovered therefrom; or, finally, the condensate may be treated in any way that shall seem necessary or advisable.

The great purity of the ammonia formed from the nitrogen com unds heretofore more particularly descril d is of especial value in the production of nitric acid, as the presence of impurities in the ammonia ordi narily causes great difficulty in the operation of the process.

The residual material formed as a byproduct in the above-described production of ammoniasuch as metal oXid, hydroxid, carbonate, and carbonmay be used in various ways,-for example, it may be calcined and mixed with coal, or mixed with coal without calcining. and coked again, being then formed into carhid and again nitrified,-thus rendering the entire process a cyclic one.

While we have above described in general outline the steps employed in producin ammonia and ammonium compounds, amv have indicated the order in which said steps may be followed and carried out, it is to be understood that the invention is not limited to the precise process described, nor is it in any way limited in respect to the order of steps other than within the scope of the appended claims.

l Vhat we claim is:

1. The process of producing ammonia and ammonium compounds, which consists in saturating with water a nitrogen-containing then heating the material decomposable with the formation of ammonia in the presence of heat and moisture to or above 450 cent. in the presence of steam.

2. The process of producing ammonia and an'imonium compounds, which consists. in treating a crude material containing nitrogen and lime with water until the lime is substantially hydrated, and then heating the 120 material to or above 450 cent. in the presence of steam.

3. T he process of producing ammonia and ammonium compounds. which consists in saturating with water a crude material con 125 taining nitrogen and resulting from the interaction of a carbid and nitrogen. and then heating the material to or above 450 cent. in the presence ot-steam.

4. The process of producing ammonia and 130 ammonium compounds which consists in treating dimetal isocyanid with water until substantially saturated then heating the material to or above 450 C. in the presence of steam.

5. The process of producing ammonia and ammonium compounds, which consists in treating a material containing nitrogen and decomposable with the formation of ammonia in the presence of heat and moisture with steam below 350 cent., and then raising thetemperature to or above 450 cent. while continuing the flow of steam over and through the mass.

6. The process of producing ammonia and ammonium compounds, which consists in treating a nitrogen-containing material decomposable with the formation of ammonia in the presence of heat and moisture with steam below 350 cent. until the material is substantially saturated, and then raising the temperature to or above 450 cent., while continulng the flow of steam 'over and throu 11 the mass.

7. The process of producing ammonia and ammonium compounds, which consists in treating nitrogen-containing material decomposable with the formation of ammonia in the presence of heat and moisture with wet steam to the point of substantial saturation, and then raising the temperature to or above 450 cent., while continuing the flow of steam over and through the mass.

8. The process of producing ammonia and ammonium compounds, which consists in treatin with steam below 350 cent. dimetal isocyanid to the point of saturation, and then raising the temperature to or above 450 cent., while continuing the flow of steam over and through the mass.

9. The process of producing ammonia and ammonium compounds, which consists in treating with water to the point of substantial saturation a product resulting from heating a carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of 1000 cent. until the reaction is completed, and then heating the material to or above 450 cent, in' the presence of steam.

10. The process of producing ammonia and ammonium compounds, which consists in treating with Steam below 350 cent. to the point of substantial saturation a product resulting from heating a carbid in an atmosphere of nitrogen gas while maintaining the monia in t e 450 cent. while continuing the flow of steam over and through the mass.

12. The process of producing ammonia and ammonium compounds, which consists in treating dicalcium isocyanid with steam below 350 cent. to the point of substanltial saturation, and then heating the material to or above 450 cent. in the presence of steam.

13. The process of producing ammonia and ammonium compounds, which consists in treating with water to the point of substantial saturation a product resulting from heating calcium carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of 1000 cent. until the reaction is completed, and then heating the material to or above 450 cent, in the presence of steam.

14. The process of producing ammonia and ammonium compounds, which consists in treating with steam below 350 cent. to the point of substantial saturation a product resulting from heating calcium carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of 1000 cent. until the reaction is completed, and then heating the material to or above 450 cent. in the presence of steam.

15. The process of producing ammonia and ammonium compounds, which consists in saturating with wat a nitrogen=containing material, decomposable with the formation of ammonia in the presence of heat and moisture, and then heating the material to or above 450 cent. in the presence of steam at atmospheric pressure.

16. The process of producing ammonia and ammonium compounds, which consists in saturatin with water a crude material containing nitrogen resulting from the interaction of a carbid and nitrogen, and then heating the material to or above 450 cent. in the presence of steam at atmospheric pressure.

17. The processof producing ammonia and ammonium compounds, which consists in treating a material containing nitrogen and decom osable with the formation of amresence of heat and moisture with steam be ow 350 cent., and then raising the temperature to or above 450 cent. while continuing the flow of steam at atmospheric pressure over and through the mass.

18. The process of producing ammonia and ammonium compounds, which consists in treating with water to the point of substantial saturation a product resulting from heating a carbid in an atmosphere of nitrogen gas while maintaining the heat at av point not in excess of 1000 cent. until the reaction is completed, and then heating the.

Ill)

and ammonium compounds, which consists in treating with steam beloug 3 fi0 cent. to the oint of substantial saturation aproduct resu ting from heating a carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of l000 and ammonium compounds, which consists in treating with Water to the point of substantial saturationa product resulting from heating calcium carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of 1000 cent. until the react-ion is completed, and then heating the material to orabove 450 cent, in the presence of steam at atmospheric pressure.

21. The process of producing ammonia and ammonium compounds, which consists in treating with steam below 350 cent. to the point of substantial saturation a product resulting .from heating calcium carbid in an atmosphere of nitrogen gas while maintaining the heat at a point not in excess of 1000 cent. until the reaction is completed, and then heating the material to or above 450 cent. in the presence of steam at atmospheric pressure. I

In testimony whereof, we the said GEORGE G. TAYLOR and Isnoxn E. KNAPP, Jr., have hereunto set our hands. 1

GEORGE G. TAYLOR. ISMOND E. KNAPP, JR.

Witnesses JOHN F. \VILL, IRENE F. GEYER.

It is hereby certified that Letters Patent No. 1,315,534, granted September 9, 1919, upon the application 0t George G. Taylor, of Grafton, and Ismond E. Knapp, of Ooraopolis, Pennsylvania, for an improvement in Processes of Producing "Ammonia end Ammonium Compounds, were erroneously issued to said inventors,

said Taylor and Knapp, as owners of said invention, whereas said Letters Patent should have been issued to James Henry Reid, of Pittsburgh, Pennsylvania, as

designer; ofthe entire interest in said invention, as shown by the record of assignments in this ofiiee; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oifice.

Signed and sealed this 25th day of November, A. D., 1919.

M. H. COULSTON,

Acting Commissioner of Patents.

,sEALJ 

